INFO: task kworker/0:4:11113 blocked for more than 120 seconds. Not tainted 4.16.0+ #288 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:4 D24008 11113 2 0x80000000 Workqueue: events cgwb_release_workfn Call Trace: context_switch kernel/sched/core.c:2848 [inline] __schedule+0x8fb/0x1ef0 kernel/sched/core.c:3490 schedule+0xf5/0x430 kernel/sched/core.c:3549 bit_wait+0x18/0x90 kernel/sched/wait_bit.c:197 __wait_on_bit+0x88/0x130 kernel/sched/wait_bit.c:48 out_of_line_wait_on_bit+0x204/0x3a0 kernel/sched/wait_bit.c:63 wait_on_bit include/linux/wait_bit.h:76 [inline] wb_shutdown+0x335/0x430 mm/backing-dev.c:377 cgwb_release_workfn+0x8b/0x622 mm/backing-dev.c:520 process_one_work+0xc97/0x1c40 kernel/workqueue.c:2113 worker_thread+0x1c3/0x1380 kernel/workqueue.c:2247 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411 Showing all locks held in the system: 2 locks held by khungtaskd/879: #0: 0000000028f45f4f (rcu_read_lock){....}, at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: 0000000028f45f4f (rcu_read_lock){....}, at: watchdog+0x1d6/0xd70 kernel/hung_task.c:249 #1: 000000005c15f6f0 (tasklist_lock){.+.+}, at: debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 1 lock held by rsyslogd/4324: #0: 00000000358fd875 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x165/0x1a0 fs/file.c:766 2 locks held by getty/4414: #0: 0000000016218176 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000bc74aa63 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4415: #0: 00000000def4b4ca (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000007dc764f4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4416: #0: 0000000049811c8b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000a1791501 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4417: #0: 00000000da34078c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000957f2cf7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4418: #0: 000000001a13f782 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000004e612b14 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4419: #0: 00000000717a444b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000089094709 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4420: #0: 00000000e73c0113 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000007adebce1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by kworker/0:4/11113: #0: 000000000a209965 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 000000000a209965 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000000a209965 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000000a209965 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:57 [inline] #0: 000000000a209965 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 000000000a209965 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 000000000a209965 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb83/0x1c40 kernel/workqueue.c:2084 #1: 000000006e2aa073 ((work_completion)(&wb->release_work)){+.+.}, at: process_one_work+0xbd9/0x1c40 kernel/workqueue.c:2088 1 lock held by syz-executor6/22344: #0: 00000000067310d3 (&evdev->mutex){+.+.}, at: evdev_ioctl_handler+0x82/0x180 drivers/input/evdev.c:1299 1 lock held by syz-executor3/22357: #0: 00000000067310d3 (&evdev->mutex){+.+.}, at: evdev_open_device drivers/input/evdev.c:429 [inline] #0: 00000000067310d3 (&evdev->mutex){+.+.}, at: evdev_open+0x312/0x5d0 drivers/input/evdev.c:522 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 879 Comm: khungtaskd Not tainted 4.16.0+ #288 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1a7/0x27d lib/dump_stack.c:53 nmi_cpu_backtrace+0x1e0/0x220 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x123/0x180 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0x969/0xd70 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 22355 Comm: syz-executor3 Not tainted 4.16.0+ #288 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0x16f/0x3c30 kernel/locking/lockdep.c:3307 RSP: 0018:ffff8801ca5e6720 EFLAGS: 00000002 RAX: 0000000000000003 RBX: 0000000000000000 RCX: 0000000000000002 RDX: ffffffff89df0640 RSI: 0000000000000000 RDI: ffffffff8858b280 RBP: ffff8801ca5e6ac0 R08: 0000000000000000 R09: 0000000000000000 R10: ffff8801ca5e6ad8 R11: 0000000000000001 R12: 1ffff100394bcd65 R13: ffffffff8858b280 R14: ffff8801c0728580 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 000000009bc26000 CR3: 000000000846a000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 rcu_lock_acquire include/linux/rcupdate.h:246 [inline] rcu_read_lock include/linux/rcupdate.h:632 [inline] lock_page_memcg+0x8f/0x320 mm/memcontrol.c:1607 page_remove_file_rmap mm/rmap.c:1213 [inline] page_remove_rmap+0x3b1/0xf40 mm/rmap.c:1298 zap_pte_range mm/memory.c:1337 [inline] zap_pmd_range mm/memory.c:1441 [inline] zap_pud_range mm/memory.c:1470 [inline] zap_p4d_range mm/memory.c:1491 [inline] unmap_page_range+0xfff/0x2330 mm/memory.c:1512 unmap_single_vma+0x15f/0x2d0 mm/memory.c:1557 unmap_vmas+0xf1/0x1b0 mm/memory.c:1587 exit_mmap+0x23a/0x500 mm/mmap.c:3027 __mmput kernel/fork.c:960 [inline] mmput+0x23d/0x700 kernel/fork.c:981 exit_mm kernel/exit.c:544 [inline] do_exit+0x9c5/0x2700 kernel/exit.c:852 do_group_exit+0x149/0x400 kernel/exit.c:968 SYSC_exit_group kernel/exit.c:979 [inline] SyS_exit_group+0x1d/0x20 kernel/exit.c:977 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f94c99 RSP: 002b:000000000844ea8c EFLAGS: 00000206 ORIG_RAX: 00000000000000fc RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Code: 84 88 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 64 0e 00 00 44 8b 1d 31 b7 2d 07 45 85 db 0f 84 16 08 00 00 48 c7 c2 40 06 df 89 <48> b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 14 02 48 c7 c0 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.032 msecs